Special-shaped shell milling clamp

Abstract

The special-shaped shell milling clamp comprises a base, a connecting shaft, a front end cover and a rear end cover, the base is installed on a machine tool workbench, the lower end face of the connecting shaft is connected, the front end cover and the rear end cover are located on the upper end face of the connecting shaft, and the rear end cover is connected with the upper end face of the connecting shaft through a bolt. The front end cover is connected with the rear end cover through bolts, positioning faces and clamping holes are machined in the front end cover and the rear end cover 6, and after the front end cover and the rear end cover are connected, the shapes of the clamping holes and the positioning faces are matched with the shape of a workpiece to be machined. According to the technical scheme, the positioning precision is high, clamping is convenient, operation is easy, machining and control of multiple spatial position elements can be completed through one-time machining, and the part machining efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of machining, in particular to a milling fixture for a special-shaped shell. Background Art

[0002] The processing of special-shaped parts has very high requirements for fixtures. First, it is necessary to determine the positioning datum of the part, connect it to the positioning fixture through the positioning datum, and then use the clamping fixture to process the part and the positioning fixture as a whole. Although it can solve the positioning and clamping of special-shaped parts with many spatial dimensions, complex external structures and unstable datums, there is also the problem that the fixture operation is too complicated. For example, the technical solution disclosed in “Processing method, fixture and fixture design method of special-shaped parts” CN202010605179.9 is to infer the position of the pad by the position of the core shaft, and use the pressure plate to press it. The pad needs to be repeatedly adjusted according to the inspection results of the two core shafts. The support of this fixture is often not strong enough, and may move and deviate when clamping, affecting the processing effect. In five-axis milling processing, the multiple spatial elements of special-shaped parts have always been a problem. Summary of the Invention

[0003] The technical problem solved by the present invention is to provide a special-shaped shell milling fixture with accurate positioning, reliable clamping and greater versatility.

[0004] The technical solution adopted by the present invention is a special-shaped shell milling fixture, including a base, a connecting shaft, a front end cover and a rear end cover, the base is mounted on a machine tool workbench, the lower end face of the connecting shaft is connected, the height of the connected base and the connecting shaft is greater than the distance between the machine tool workbench and the spindle box, the front end cover and the rear end cover are located on the upper end face of the connecting shaft, wherein the rear end cover is connected to the upper end face of the connecting shaft by bolts, and the front end cover is connected to the rear end cover by bolts, and positioning surfaces and clamping holes are machined on the front end cover and the rear end cover, and after the front end cover and the rear end cover are connected, the shapes of the clamping holes and the positioning surfaces are adapted to the outer shape of the workpiece to be machined;

[0005] The surface where the front end cover and the rear end cover are fitted and connected is the connecting surface. The front end cover and the rear end cover are integrally processed and formed and then cut into two parts. The size of the clamping hole is consistent with the size of the corresponding part of the workpiece to be processed. After cutting, a connecting surface is formed on the front end cover and the rear end cover. The cutting thickness is greater than 0.5mm and less than 1mm.

[0006] The clamping holes and positioning surfaces on the front cover and the rear cover are symmetrical.

[0007] The clamping holes include square holes and circular holes, and both the square holes and the circular holes are adapted to the outer dimensions of the workpiece.

[0008] Positioning pin holes are processed on the connecting surface, and the front cover and the rear cover are positioned relative to each other using pins.

[0009] A stepped hole is designed inside the connecting shaft.

[0010] The invention has the advantages of high repeatability, convenient clamping, simple operation, and the ability to complete the processing and control of multiple spatial position elements in one operation, thereby improving the processing efficiency of parts and ensuring quality consistency. The versatility of the invention can be enhanced by replacing the screw sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the present invention.

[0012] Figure 2 Schematic diagram of the connecting shaft.

[0013] Figure 3 A schematic diagram of the base.

[0014] Figure 4 Schematic diagram of the front end cover.

[0015] Figure 5 Schematic diagram of the rear end cover.

[0016] Figure 6 Schematic diagram of the workpiece clamping method for processing.

[0017] Markings in the figure are: 3-connecting shaft, 31-placement groove, 4-base, 5-front cover, 6-rear cover, 7-positioning surface, 71-clamping hole, 8-workpiece, 81-supported surface, 9-connecting surface. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings.

[0019] The milling fixture for special-shaped shell parts of the present application includes a front cover, a rear cover, a connecting shaft, a base, pins, and bolts. The front cover 5 and the rear cover 6 form a clamping body, which is provided with a clamping hole 71 for clamping and a positioning surface 7 for positioning; a plurality of threaded holes are provided at both ends of the connecting shaft 3, one end of which is connected to the base 4, and through this cooperation, the connecting shaft 3 is fixed on the base; the other end is connected to the clamping body that fixes the workpiece to be processed to complete the clamping of the workpiece to be processed. A countersunk keyway is provided on the base 4, which is used to fix the fixture as a whole on the workbench of the machine tool. The front and rear end covers of the clamping body are both provided with positioning pin holes to prevent the front cover 5 and the rear end cover 6 from moving during assembly. In addition, a notch with a depth of about 1 mm is provided on the connecting shaft 3 for fixing and repeatedly positioning the clamping body.

[0020] Among them, the front end cover 5 and the rear end cover 6 that make up the clamping body are integrally formed and then cut into two parts. The cutting gap is required to be greater than 0.5mm and less than 1mm. Before cutting, the size of the clamping hole 71 is consistent with the size of the corresponding part of the workpiece to be processed. During cutting, symmetrical cutting is performed along the axis of the clamping hole. After cutting, the clamping hole 71 falls on half of each of the front end cover 5 and the rear end cover 6. The cutting removal amount is maintained at 0.5mm-1mm, which means that after cutting, the size of the clamping hole 71 and the corresponding part of the workpiece are not completely consistent. The hole diameter is reduced by 0.5mm-1mm. When the front end cover 5 and the rear end cover 6 are accurately positioned and clamped, a clamping force will be generated on the workpiece 8. Since some workpieces are thin-walled parts, the 0.5mm-1mm margin can fix the workpiece with the minimum clamping force to prevent the workpiece from being deformed due to excessive clamping force. During assembly, the position is positioned through the positioning pin holes of the front end cover 5 and the rear end cover 6, and the connection and fixation are carried out through threaded fitting.

[0021] Since the worktable must be flipped during workpiece processing, the combined height of the base 4 and the connecting shaft 3 is greater than the distance between the machine tool worktable and the spindle box to avoid collisions. The connecting shaft 3 is internally designed with a stepped hole to reduce the overall weight of the fixture.

[0022] Working principle and usage process: When in use, the first step is to fix the base 4 to the machine tool workbench, and then use the bolt 1 to connect the connecting shaft 3 to the base 4. The bottom of the connecting shaft 3 is designed with a threaded connection hole, which is compatible with the base 4; the second step is to connect the rear end cover 6 to the connecting shaft 3 through the threaded hole. The upper end face of the connecting shaft 3 is designed with a threaded connection hole, which is compatible with the rear end cover; the third step is to use the clamping holes 71 on the front end cover 5 and the rear end cover 6 to clamp and fix the clamped surface 81 on the workpiece 8, and the reference surface and positioning surface 7 of the workpiece 8 are in contact. The front end cover 5 and the rear end cover 6 are positioned and connected with pins and bolts, and the workpiece 8 is clamped, and finally the assembly of the fixture and the workpiece 8 to be processed is completed.

[0023] The upper end surface of the connecting shaft 3 is designed with a placement groove to limit the position of the front cover, facilitating repeated assembly and positioning, making it convenient and reliable to install. Furthermore, the front cover 5 and rear cover 6 are machined integrally and then cut. The cut is less than 1mm and greater than 0.5mm, ensuring that tension is achieved without causing the part to lose its grip. This provides reliable clamping force and prevents deformation caused by excessive stress. The clamping area of ​​the part is thin-walled. The clamping holes of the front cover 5 and rear cover 6 can be adjusted according to the outer diameter of the workpiece 8 to be machined and the square contour, enhancing the versatility of the fixture, saving processing costs, and improving work efficiency.

[0024] The milling fixture for special-shaped shell parts disclosed in this application features convenient clamping, simple operation, and repeatable positioning and fixing. While providing reliable clamping, it can complete the machining of multiple spatial elements of a part in one go. By varying the sizes of the positioning holes and square holes in the clamp body, it can be applied to the milling of a variety of shell parts. This fixture solves the machining issues of special-shaped shell parts with complex shapes and irregular datums, enabling the completion of multiple spatial elements of a part in one go, ensuring consistent part quality and improving machining efficiency.

Claims

1. Milling fixture for special-shaped shells, characterized by: The invention comprises a base (4), a connecting shaft (3), a front end cover (5) and a rear end cover (6), wherein the base (4) is mounted on a machine tool workbench and is connected to the lower end surface of the connecting shaft (3); the height of the connected base (1) and the connecting shaft (3) is greater than the distance between the machine tool workbench and the spindle box; the front end cover (5) and the rear end cover (6) are located on the upper end surface of the connecting shaft (3); the rear end cover (6) is connected to the upper end surface of the connecting shaft (3) by bolts; the front end cover (5) is connected to the rear end cover (6) by bolts; a positioning surface (7) and a clamping hole (71) are processed on the front end cover (5) and the rear end cover (6); after the front end cover (5) and the rear end cover (6) are connected, the shapes of the clamping hole (71) and the positioning surface (7) are adapted to the shape of the workpiece to be processed.

2. The special-shaped shell milling fixture according to claim 1, characterized in that: The surface where the front end cover (5) and the rear end cover (6) are joined and connected is a connecting surface (9). The front end cover (5) and the rear end cover (6) are formed as one piece and then cut into two parts. The size of the clamping hole (71) is consistent with the size of the corresponding part of the workpiece to be processed. After cutting, the connecting surface (9) is formed on the front end cover (5) and the rear end cover (6). The thickness of the cut removal is greater than 0.5 mm and less than 1 mm.

3. The special-shaped shell milling fixture according to claim 2, characterized in that: The clamping holes (71) and the positioning surfaces (7) on the front end cover (5) and the rear end cover (6) are in a symmetrical state.

4. The special-shaped shell milling fixture according to claim 3, characterized in that: The clamping holes include square holes and circular holes, and both the square holes and the circular holes are adapted to the outer dimensions of the workpiece.

5. The special-shaped shell milling fixture according to claim 2, characterized in that: Positioning pin holes are machined on the connecting surface (9), and the front end cover (5) and the rear end cover (6) are positioned relative to each other using pins.

6. The special-shaped shell milling fixture according to claim 1, characterized in that: The connecting shaft (3) is internally designed with a stepped hole.

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